Before the present invention was made, several benzoyl urea compounds that inhibit formation of chitin had been developed, including the well known commercial pesticide, N-(2,6-dichlorobenzoyl)-N'-(4-chloro- or 3,4-dichloro-phenyl) urea. European Patent Publication Nos. 093,976 and 093,977 disclose 3,5-bis(trifluoromethyl)phenyl benzoyl urea derivatives whose structures are similar to that of the present invention. However, they exhibit weak pesticidal activity against Diamond backmoth even at concentrations as high as 1 ppm. International Publication No. WO 94/03066 teaches a benzoyl ureido pyridyl phenyl ether derivative, which is undesirable because it can be prepared only by means of an intricate and expensive process. European Patent Publication No. 232,080 discloses a 2,5-difluoro4-chlorophenyl benzoyl urea derivative whose LC.sub.50 value against Tobacco cutworm ranges from 0.3 to 0.4 ppm.
The benzoyl urea derivatives of the prior art thus exhibited weak pesticidal activity only against certain pests, or could be prepared only by means of complicated and uneconomic processes.